Safety condensate overflow system

ABSTRACT

The present invention provides a drain system for a central air conditioning system wherein a refrigeration system evaporator is mounted over a drain pan and is arranged in a cabinet. The pan collects the condensate from the evaporator and is provided with primary drain passageway for normal draining operation of the pan and a secondary drain passageway operable in the event the primary drain passageway is blocked for carrying the condensate away from the cabinet interior. A safety drain is provided in the secondary drain passageway that will automatically allow evacuation of condensate from the drain pan in the event both primary and secondary drain passageways are blocked.

United States Patent Irwin Oct. 7, 1975 [54] SAFETY CONDENSATE OVERFLOW3,212,288 10/1965 Herbert 62/290 SYSTEM 3,596,475 8/1971 Berger 62/291Inventor: John W. Irwin, Trenton, NJ.

General Electric Company, Louisville, Ky.

Filed: Sept. 5, 1974 Appl. No.: 503,259

Assignee:

References Cited UNITED STATES PATENTS 3/1933 Moore 62/288 9/1961 Crider62/285 7/1963 Makuh 62/285 Primary Examiner-William J Wye [57] ABSTRACTThe present invention provides a drain system for a central airconditioning system wherein a refrigeration system evaporator is mountedover a drain pan and is arranged in a cabinet. The pan collects thecondensate from the evaporator and is provided with primary drainpassageway for normal draining operation of the pan and a secondarydrain passageway operable in the event the primary drain passageway isblocked for carrying the condensate away from the cabinet interior. Asafety drain is provided in the secondary drain passageway that willautomatically allow evacuation of condensate from the drain pan in theevent both primary and secondary drain passageways are blocked.

4 Claims,'3 Drawing Figures US. Patent Oct. 7,1975

SAFETY CONDENSATE OVERFLOW SYSTEM BACKGROUND OF THE INVENTION In acentralized air conditioning system the evaporator coil is customarilymounted in a cabinet which also contains a blower for moving air throughthe evaporator and into the area to be cooled. A drain pan is usuallylocated below the evaporator in a manner that collects condensatetherefrom. It is important that the condensate collected in the pan bedrained out of the cabinet so that it does not come into contact withelectrically operable components in the cabinet. It has been commonpractice therefore to provide the pan with a primary drain means thateffectively directs the condensate out of the cabinet and which isusually adapted to be suitably connected to a drain system. Provisionshave also been made available in air conditioning equipment for asecondary drain to direct condensate from the cabinet interior in theevent the primary drain becomes ineffective in carrying away condensate.In many installations both primary and secondary drain means areconnected to a drain system of the structure to be conditioned byconduits that are arranged outside of the cabinet at the time the airconditioning system is installed. In the event both of these conduitsbecome clogged or pinched condensate would then back up into the pan andwould overflow into the cabinet interior wherein it may come intocontact with one of the electrically operable components causing ahazardous condition.

SUMMARY OF THE INVENTION An air conditioning apparatus having a cabinetincluding a refrigeration evaporator arranged over a drain means. Thedrain means includes a base pan having a primary drain for carrying offcondensate from the evaporator to a location exterior from the cabinet,and a secondary drain means for carrying off condensate in the event theprimary drain is clogged. The secondary drain means includes a safetydrain means which automatically carries off the condensate in the eventboth the primary and secondary drain outlets are clogged.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial elevational viewof an air conditioning apparatus incorporating the present invention;

FIG. 2 is an enlarged view taken substantially along lines 22 of FIG. 1;and

FIG. 3 is a side elevational view taken along lines 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there isshown a cabinet which may be part of a hot air furnace or central airconditioner which includes a blower or air handling means (not shown)for moving air through the furnace in the direction indicated generallyby the arrows. Located in a distribution plenum 12 is an A-coil orinverted V-shaped evaporator assembly or heat exchanger indicatedgenerally at 14.

The evaporator 14 is of conventional design and is formed from a seriesof flat, thin plates and has the usual refrigerant tubing 16 passingtherethrough as part of the refrigerant system. Other conventionalcomponents such as a base pan 18 including a bottom wall 26 and sidewalls 24 is provided wherein the lower edges of the evaporator and morespecifically, the plates are located in the pan 18. The base pan 18 isconveniently located so as to collect all of the condensate that maydrip off the evaporator 14.

Referring now to FIGS. 2 and 3, a drain outlet 20 having an opening 22is provided in one side wall 24 of the pan 18. As shown in FIG. 3 thedrain opening 22 is arranged adjacent the bottom wall 26 of the pan andextends beyond the outer wall 28 of the cabinet. The outlet 20 hasconnected thereto a drain conduit 30 for carrying the condensate awayfrom the cabinet 10. It should be clearly understood that the condensatecollected in the pan 18 must be directed outside of the cabinet interiorso that it does not come into contact with any of the electricalcomponents of the system.

In accordance with the embodiment of the present invention shown, asecondary drain tube 32 is provided which as will hereafter be describedin detail carries condensate water. away from the base pan l8 and to theexterior of the cabinet 10 in the event the primary drain opening 22 orthe conduit 30 becomes clogged. The secondary drain tube 32 has aportion arranged in the base pan including an inlet opening 34 and anoutlet portion including an outlet opening 36 extending through the sidewall 24 and projecting beyond the outer extremities of the cabinet. Thetube 32 is conveniently secured to the wall 24. The vertical position ofthe opening 34 as best seen in FIG. 3 is intermediate the lower portionof the opening 22 and the upper edge portion of the base pan wall 24.Since the opening 34 must be effective to drain condensate out of thepan 18 when condensate reaches a predetermined level it is convenientlylocated adjacent the opening 22. The exact vertical position of theopening 34 is determined by the air pressure and its effect on thecondensate level in the general area of the drain opening which may begreater or less than the air pressure in other locations of the base pan18. In the event the conduit 30 is clogged or restricted the condensatewater will enter the opening 34 at its set level and direct condensatewater out of opening 36 and into a convenient conduit 38 which isarranged over the outlet portion of the tube 32.

While the provision of a secondary drain system provides a measure ofsafety in that a drain for the condensate is provided in the event theprimary drain is clogged, there is always the risk of both drains beingrendered ineffective. Both conduits 30 and 38 are connected to theirrespective drains at the time the furnace is installed and areconveniently arranged outside of the cabinet 10. This makes thesevulnerable and as a result both may be damaged and pinched and as aresult render the draining system inactive. It is also possible thatwhile one drain may be pinched, the other may become clogged with debrisor particles entering the conduits from the pan 18. In any event theclogging of both the primary and secondary drain systems would permitcondensate water to raise to a level above the walls 24 of the pan l8and spill over into the interior of the cabinet where the water may comeinto contact with the electrical components and create a potentialhazardous condition.

The present invention is directed particularly to the provision of asafety drain system in the secondary drain tube 32 that is effective in.automatically directing condensate water out of the drain pan l8 andcabinet in the event both the primary and secondary drain systems arerendered inoperative.

To this end a relief drain opening 40, FIG. 2, is provided in thesecondary drain tube 32 portion extending outside of the pan 18. Theopening 40 is arranged in the upper portion of the exterior radial wallof the tube 32. This upper location allows flow of water past opening 40when the secondary drain system is operating normally without anyobstruction to the flow therethrough. In operation when the primarydrain 22 becomes inoperative as by clogging or by conduit 30 beingpinched, water from the pan 18 is drained through the secondary tube 38past the relief opening 40 and into conduit 38 which directs it-into anappropriate drain system. In summary, in the event conduit 38 becomespinched or clogged water will flow out of opening 40 and as a resultdoes not back up in the pan l8 and overflow into the interior of thecabinet 10.

Provision is also made by the present embodiment of the invention toinsure that when water flows out of opening 40 it is directed away fromthe outer extremities of the cabinet 10. Accordingly, a diverter means42 is connected to the side wall 24 of the base pan 18. The diverter isgenerally U-shaped and includes a bottom wall 44 located below theexterior portion of the safety drain tube 32, and upwardly extendingsubstantially parallel side wall portions 46 arranged on each side ofthe exterior portion of the safety drain tube 32. As seen best in FIG. 2the diverter 42 projects from the side wall 24 of base pan 18 to aposition substantially past the opening 40 and outer extremities of thecabient 10 so that when water flows out of opening 40 it is received inthe U-shaped diverter and carried away from cabinet 10 independent ofthe secondary drain system.

During the installation of the drain conduit 38 over the exterior endportion of the tube 32 it may inadvertently be positioned over therelief drain 40 and render the safety drain system inoperative. To guardagainst and prevent this inadvertent closing of the drain 40, the endportion of each of the walls 46 is bent inwardly to form guard members48 adjacent the upper half portion of the tube 32. As seen in FIG. 3 thespacing of the guard member 48 relative to the tube 32 effectively actsas a stop to prevent the installation of conduit 38 to a position overthe relief opening 40.

While there has been shown and described a specific embodiment of theinvention, it will be understood that it is not limited thereto and itis intended by the appended claims to cover all such modifications asfall within the true spirit and scope of this invention.

What is claimed is:

1. In an air conditioning apparatus having a cabinet includingrefrigeration system evaporator means arranged in said cabinet, anddrain means positioned below said evaporator for receiving condensationfrom said evaporator, said drain means comprising:

a base pan arranged in said cabinet including side walls;

a primary drain means arranged in the lower portion of one of said sidewalls having one end communicating with said base pan and its other endadapted to projectbeyond the outer extremities of said cabinet fordirecting condensate out of said cabinet; secondary drain tube meanshaving a continuous side wall including an inlet end disposed in saidbase pan between the lower end of said primary drain means and the upperextremities of said side walls andan outlet end disposed outside of saidcabinet for directing condensate from said base pan to the exterior ofsaid cabinet when the condensate in said pan reaches the predeterminedlevel of said inlet; and

a safety drain means including a relief drain opening located in theupper half of said secondary tube means side wall in an area outside ofsaid base pan providing an outlet for condensate entering said inletfrom said base pan when said secondary drain outlet end is closed.

2. The invention of claim 1 wherein diverter means below said safetyopening projecting from the outer surface of said base pan side wall toa position exterior of said cabinet for receiving condensate from saidrelief drain opening and diverting it away from said cabinet when saidsecondary drain outlet end is closed.

3. The invention of claim 2 wherein said diverter means includes abottom wall arranged below said secondary drain tube and side wallsprojecting upwardly from said bottom wall along opposite sides of saiddrain tube means in the area of said relief drain opening.

4. The invention of claim 3 wherein the outlet end of said secondarydrain tube is adapted to receive a flexible extension tube, and saiddiverter means side walls having portions bent toward each other to aposition adjacent the upper portion of the peripheral wall of saidsecondary drain tube and downstream from said relief opening to preventsaid flexible extension from being inserted to a position over saidrelief opening.

1. In an air conditioning apparatus having a cabinet includingrefrigeration system evaporator means arranged in said cabinet, anddrain means positioned below said evaporator for receiving condensationfrom said evaporator, said drain means comprising: a base pan arrangedin said cabinet including side walls; a primary drain means arranged inthe lower portion of one of said side walls having one end communicatingwith said base pan and its other end adapted to project beyond the outerextremities of said cabinet for directing condensate out of saidcabinet; a secondary drain tube means having a continuous side wallincluding an inlet end disposed in said base pan between the lower endof said primary drain means and the upper extremities of said side wallsand an outlet end disposed outside of said cabinet for directingcondensate from said base pan to the exterior of said cabinet when thecondensate in said pan reaches the predetermined level of said inlet;and a safety drain means including a relief drain opening located in theupper half of said secondary tube means side wall in an area outside ofsaid base pan providing an outlet for condensate entering said inletfrom said base pan when said secondary drain outlet end is closed. 2.The invention of claim 1 wherein diverter means below said safetyopening projecting from the outer surface of said base pan side wall toa position exterior of said cabinet for receiving condensate from saidrelief drain opening and diverting it away from saiD cabinet when saidsecondary drain outlet end is closed.
 3. The invention of claim 2wherein said diverter means includes a bottom wall arranged below saidsecondary drain tube and side walls projecting upwardly from said bottomwall along opposite sides of said drain tube means in the area of saidrelief drain opening.
 4. The invention of claim 3 wherein the outlet endof said secondary drain tube is adapted to receive a flexible extensiontube, and said diverter means side walls having portions bent towardeach other to a position adjacent the upper portion of the peripheralwall of said secondary drain tube and downstream from said reliefopening to prevent said flexible extension from being inserted to aposition over said relief opening.